Jun 12 MS.pdf
Mark Scheme – General Certificate of Education (A-level) Chemistry – Unit 1: Foundation Chemistry – June 2012
Electron gun / high speed/high energy electrons
Not just electrons.
Not highly charged electrons.
Knock out electron(s)
Remove an electron.
Rb(g) → Rb+(g) + e(-)
Rb(g) + e(-) → Rb+(g) + 2e(-)
Rb(g) - e(-) → Rb+(g)
Ignore state symbols for electron.
Rb is a bigger (atom) / e further from nucleus / electron
lost from a higher energy level/ More shielding in Rb /
less attraction of nucleus in Rb for outer electron / more
Answer should refer to Rb not Rb molecule.
If converse stated it must be obvious it refers to Na
Answer should be comparative.
s / block s / group s
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1
Allow 3d10 before 4s2
Allow in any order.
These answers only.
Allow answers in words.
Ignore any sum(s) shown to work out the answers.